Human and Natural Forcings of Critical Zone Dynamics and Evolution at the Calhoun Critical Zone Observatory

Duke University, Durham NC

Investigators

Abstract

The Critical Zone is a new concept for the biological and geological system that extends from the upper leaves of plants to the groundwater deep below the soil. Scientists consider these systems to be "integrated" because aboveground climate, plants, animals, and human management all interact with the belowground biology, chemistry, and physics from surface soils to deep aquifers. A new Calhoun Critical Zone Observatory (CZO) is located in the USA's Southern Piedmont that extends from Virginia to Alabama, a region characterized by ancient, deep, and highly weathered landscapes that between 1800 to 1950 experienced some of the most severe agricultural soil erosion and land and water degradation in America. The new Calhoun-CZO leverages more than 60 years of research on land degradation and recovery based at the USDA Forest Service's Calhoun Experimental Forest in Union County, SC. The CZO researchers and educators are from Duke University, University of Georgia, Georgia Tech, University of Kansas, Mississippi State University, Roanoke College, as well as the USDA Forest Service. A key objective of the Calhoun CZO is to help integrate land management, disturbance, and recovery into CZ science. To that end, the scientists include hydrologists, soil scientists, agriculturists and foresters, geochemists, ecologists, and modelers but also an environmental historian and anthropologist. The overall hypothesis is that land use accelerates CZ processes associated with vegetation, atmosphere, water, and surface soils, thereby stressing temporal and spatial networks that connect surface and deep subsurface components and processes of the CZ. Land degradation may even isolate the CZ's surface from its subsurface components with adverse long-term consequences to water quality, soil fertility, and plant productivity. Researchers will focus their studies on CZ evolution, rates of recovery from land degradation, and CZ re-integration. The Calhoun-CZO is a center for research and education. The CZO is linked to a Duke University IGERT-training center on intelligent sensor networks, annual CZO science meetings will have oral and poster presentations, discussions, and training sessions that involve scientists and students on equal footing. We plan several kinds of outreach efforts to local, regional, and national publics with multi-media science, history, and community-based pieces from hardcover books to op-eds to Facebook and Twitter. An important emphasis of the CZO is on undergraduate research and education. Central to this effort will be the development of a set of classroom-tested, web-based laboratory and classroom activities for undergraduates and advanced high school students based, in part, on real-time and historic data from the Calhoun CZO.